Selector switch metering circuit



Oct. 10, 1950 C, E, LOMAX 2,525,417

SELECTOR SWITCH METERING CIRCUIT Filed Jan. 2, 1947 SEL.

'MLU u--n dan n--D INVENTOR. CLARENCE E. LOMAX BY I/ l I ATTORNEY Patented Oct. 10, 1950 SELECTOR SWITCH METERING CIRCUIT Clarence E. Lomax, Chicagmlll., assigner to Au` tomatic Electric Laboratories, Inc., Chicago, Ill., a corporation of Delaware f Application January 2, 1947, Serial No. '719,650

4 Claims.

This invention relates in general to automatic switches in automatic telephone systems and more particularly to a novel circuit arrangement for metering overflow calls.

The object of the invention is to provide a novel system for metering overow calls in an efficient and accurate manner and to provide exacting level or group level overflow supervision.

A feature of the invention is the manner in which a vertical bank and an associated vertical wiper are arranged to operate an overflow meter.

A further feature is the manner in which a plurality of meters may be connected in various arrangements to the vertical bank and thereby provide supervision for any level or group of levels of the associated switches.

Another feature is the manner in which a cam relay is arranged to prepare the operating circuit and the line relay and release relay are operated to complete the operating circuit over the vertical bank to the overflow meters.

The invention, bo-th as to its organization and method of operation together with further obiects and advantages thereof, will best be understood by reference to the following specication and the accompanying drawing.

Referring now to the drawing, the automatic switch there illustrated incorporates the features of the applicants invention. The selector comprises incoming conductors |3|, |32 and |33 and is controlled to operate by impulses received over these conductors to position wipers |34, |35 and |36 in a well-known manner opposite a desired group of bank contacts. The switch also includes an auxiliary contact bank I5| and a vertical wiper |53 of the type disclosed in British Patent 517,702 issued February 6, 1940 in which the vertical wiper moves vertically with the carriage shaft, and is free to. rotate thereon and thereby remain engaged with its bank while the switch effects rotary movement of wipers |34, |35, and |36. A portion of a succeeding selector switch similar to the one shown in detail has been shown in block form as connected to one of the contacts of the switch bank accessible by wipers |34, |35 and |36. The contacts of the auxiliary bank are individually connected to jacks which are in turn convenient to a plurality of meters.

The selector is of the battery searching type and consists essentially of a well-known Strowger vertical and rotary switch having off normal springs |31 and cam springs |38 used in conjunction with a circuit including testing relay l0, switch through relay 20, electro polarized line relay 30, release relay 4l), series relay 50, cam slave relay 6|), off normal relay lll, changeover relay B0, vertical magnet 90, release magnet |00, and rotary magnet I I0, their associated contacts and conductors.

It will now be assumed that the selector is seized over the incoming conductors |3| to |33. A loop circuit is thereby closed for line relay 33 and series relay 5|). Ground is connected to relay B0 over contacts 'i4 and conductor |33. Ref lay 8i] operates and at its contacts 8| prepares a holding circuit for itself and an operating 'cir-v cuit for vertical magnet 9U, at its contacts 32 opens a point in the operating circuit for release magnet |30, and at its contacts 33 opens a point in the operating circuit to rotary magnet IIB. Relay 3|] operates and at its contacts 3| completes an operating circuit over contacts 2| to relay 4l). Relay 5|) operates at the same time and at its contacts 5| completes a holding circuit to relay 40. Relay 4U operates and at its contacts 4| completes an auxiliary holding cir-L cuit for relay 8D over contacts '|4, at its contacts 42 completes an operating circuit to cam relay over normally closed cam springs |38, and at its contacts 43 prepares a point in the operating circuit to vertical magnet 90. Relay 60 operates and at its contacts 32 connects dial tone to conductor |3|, at its contacts 63 completes an energizing circuit for the third winding of relayA 3B over contacts E3 and i3, at its contacts 64 prepares a point in the circuit to the vertical magnet 99 and changeover magnet 8U, at its contacts 63 prepares an operating circuit for testing relay I0, at its contacts 61 prepares a point in the oper-l ating circuit 'for switch through relay 2S.V The selector is now prepared for receipt of a series of impulses over the incoming conductors, 'relays 30, 40, 5|.'I,l 60, and 8|] being in an energized con"- dition.

On receipt of the first break of the first im pulse, line relays 3U and 50 de-energize. Line relay 30 at its contacts 3| opens the operating circuit to relay 40, and at its contacts 32 completes an operating circuit to vertical magnet over contacts 21, 32, 43, 64, and 3|. Vertical magnet 90 operates and elevates the wipers |34 to |36 one step whereby they are positioned in a well-known manner opposite the rst level of bank contacts in the associated contact field. The wiper |50 is likewise positioned on the first contact of the auxiliary contact bank |5| which is common to the contact field in said first level. Incident to this first vertical step, the vertical off normal springs |31 are closed and an operatf- 3 ing circuit is completed over same to relay 1D. Relay 10 operates and at its contacts 12 removes dial tone from the line, at its contacts 13 inserts resistance |48 in series with the operating circuit for the third winding of polarized relay 30, at its contacts 15 completes a holding circuit to relay .80 over contacts 21, 32, 43, 64, 8l and 15, at its contacts 16 prepares a point in the operating circuit to release magnet |80, and at its contacts 11 prepares a point in the operating'circuit to rotary magnet I0.

The vertical magnet elevates the wipers a number of levels relative to the number of impulses received. Relays 4U and 9 0 are slow to release and remain operated during the series of incoming impulses.

A short period after the cessation of the impulses of the first digit, relay 8G releases, and at its contacts 8| opens the operating circuit te the. Vertical magnet. at its contacts 32 Closes a further point in the circuit to release magnet |00, and at its contacts 83 closes a self-interrupting operating circuit tol rotary magnet Il@ over contacts 61, I2, 28, 11 and 83. If all trunk lines on the selected level are busy, the switch wipers |39, |375 and |36v will be stepped in a well-known manner to the eleventh position While the vertical Wiper remains` engaged with the level contact Yon the auxiliary bank, whereupon the cam springs |38 are operated to open` the operating circuit to relay Sii. Relay E@ releases and at its contacts 5| applies busy tone to the line |3| over contacts 1|, 6| and 2i, at its contacts 62 further opens the dial tone circuit to line |3 ,s at its contacts 63 opens the third winding circuit of line relay 3G, at its contacts 65 further opens the operating circuit to the vertical magnet, at its contacts 65 prepares an operating circuit over the wiper Hic to the level or group meten depending upon the existing meter connections to the co-ntact with which the vertical Wiper |5 is engaged. The callingv party on receiptV of the busy tone restores his handset which opens the operating circuit to relays 3Q and 50'. Relays 3Q and 5t release and at their respective contacts 3| and 5| open the operating circuit to relay 4G. Relay 4 0 holds for a` short period. Assuming the vertical wiper |55 isV engaged with the eighth contact, a temporaryV circuit is completed over contacts 2l, Si?, 33, B3, wiper lr, the eighth contact of the auxiliary bank, throughY jack box |52 to the level meter |51.l After a short period relay 4t releases and opens the aforedescribed circuit to the level meter. With this arrangement a plurality o f selectors of a group will be connected as illustrated by incoming leads |53 and each selector will ordinarily register all trunks busy when they rotate to the overiiow position. The jacks in the jack bex |52 are connected to the contacts on, auxiliary bank |5 by a group of conducto-rs, each conductor being individual to a contact and a jack. Various circuit arrangements can be devised by employing a various number of meters and jumpers. In the arrangement shown a. level meter is connected to the jack for `the eighth level of the selector and jumpers are inserted into theA remaining jacks to multiple the remaining levels to a group meter. The all trunk busy periods of the eighth level will thereby be monitored individually, but the levels of contacts corresponding to the multipled contacts will be monitored as a group without indicatingr which level has all trunks busy. Many other arrangements are immediately apparent andy further detail is unnecessary. Relay 40 on releasing at its contacts 44 completes a circuit to release magn net |00 over contacts 21, 32, 44, 32 and 1S. Magu net Uil operates and releases the switch thereby opening the operating circuit to relay '16. Relay 10 restores and the switch is ready for a subsequent call.

If the selected level is not busy the switch will stop rotating when the wiper |36 inds an idle trunk with battery potential thereon. A circuit will then be completed for relay l0 over contacts 66. Relay l operates and at its contacts completes an operating circuit for relay 25 over contacts $1 and at its contacts l2 opens the operating circuit to rotary magnet I I. The rotary motion is thereby stopped. Relay 2@ operates and at its contacts 2| and 23 opens the operating circuit to line relays 30 and 50, at its contacts 22 and 24 connects lines |3| and 532 to |34 and |35, at its contacts 25 connects line |33 to line |36 and thereby extends the C lead through the selector, `at its contacts 2%? closes a temporary holding circuit for itself over contacts @l andl fit, at its Cntact 2l opens a further point on the release magnet circuit and at its contact 28 opens a further point in the rotaryrmagnet circuit. e

.Relays 3,6 and 5|! restoreand'at their respective contacts 3| and 5i open the circuit to relay 40. Relay @it at its Contacts 3 opens the holding circuit tov relay 6 0, Relay @t releases and opens the operating circuits QQ relays it and 20 at its contacts 66 and 6l.A Relays 2i? and 'it remain operated during the completed connection, relay 2li being maintained in the energized condition by a ground. returned over wiper lB from a succeeding switch.

Release of the switch is. effected in a normal manner. When the calling party hangs up ground is removed from conductor 36 and relay 2|)l releases. Relay 2li at its contacts 2l completes an operating circuit to release magnet |96 over contacts 21, 32, ali, 82 and 1.3. Release magnet |00, operates and effectsV rel-ease of the selector switch in a well-known manner. Oi normal springs |31 thereuponl open the circuit to off normal4 relay 1,0 which releases., and at its contacts 'L6-V opens the.-v operating circuit to release magnet |00. The. release magnet. restores and the selector is restored to normal.

While a'particular embodiment of the inven tion has been described,l it will be understood that various modications may be made therein which are Within the true.. spirit'y and scope of the invention.

l. ln a twofmotien automatic switch, a vertical bank havinga plurality of contacts and a rotary ban-k having a plurality of Vcontacts ar ranged ina plurality of levels, each contact of said vertical bank being associated. with a different Vone of saidL rotary bank contact levels, a meter connected to one of said contacts on said vertical bank, means for busying certainy of, said rotary bank contacts, a, vertical, wiper on said switch having access to said,vertical,banlgcontacts, other wipers on'r said` switchlhaving access tosaid rotary bank contact levels, means for operating said switchl inY a vertical motion to simultaneously moveY said vertical Wiper intol engagement with said meter contactandposition saidother wipers opposite the rotary bank level associated with said meter contact, means for operating said switch in a rotary motionto move only said other-Wipers across saidcontacts of said rotaryY bank level associated with said meter contact while maintaining said vertical wiper in engagement with said meter contact, a circuit including said meter contact and said vertical wiper for operating said meter, and means for completing said circuit to operate said meter in case all said contacts of said rotary bank level associated with said meter contact were busy during said rotary motion of said switch.

2. In a two-motion automatic switch, a vertical bank having a plurality of contacts and a rotary bankhaving a plurality of contacts arranged in a plurality of levels, each contact of said vertical bank being associated with a different one of said rotary bank contact levels, a meter connected to one of said contacts on said vertical bank, means for busying certain of said rotary bank contacts, a vertical wiper on said switch having access to said vertical bank contacts, other wipers on said switch having access to said rotary bank contact levels, means for operating said switch in a vertical motion to simultaneously move said vertical wiper into engagement with said meter contact and position said other wipers opposite the rotary bank level associated with said meter contact, means for operating said switch in a rotary motion to move only said other wipers across said contacts of said rotary bank level associated with said meter contact while maintaining said vertical wiper in engagement with said meter contact, a cam relay included in said switch, circuit means for operating said cam relay, cam springs included in said cam relay circuit operated in case all said con tacts of said rotary bank level associated with said meter contact were busy during said rotary motion to open said cam relay operating circuit for releasing said operated cam relay, a circuit including said meter contact and said vertical wiper for operating said meter, and contacts controlled responsive to said release of said cam relay for completing said meter circuit to operate said meter.

3. In a two-motion automatic switch, a vertical bank having a plurality of contacts and a rotary bank having a plurality of contacts arranged in a plurality of levels, each contact oi said vertical bank being associated with a different one of said rotary bank contact levels, a meter connected to one of said contacts on said vertical bank, means for busying certain of said rotary bank contacts, a vertical wiper on said switch having access to said vertical bank contacts, other wipers on said switch having access to said rotary bank contact levels, means for operating said switch in a vertical motion to simultaneously move said vertical wipers into engagement with said meter contact and position` said other wipers opposite the rotary bank level associated with said meter contact, means for operating said switch in a rotary motion to move only said other wipers across said contacts of said rotary bank level associated with said meter contacts while maintaining said vertical wiper in engagement with said meter contact, a line relay and a slow-to-release relay associated with said switch, circuit means for operating and releasing said line relay, other circuit means controlled by said operation of said line relay for operating said slow-to-release relay, additional circuit means including said vertical wiper and said engaged meter contact for operating said meter, means for preparing said meter circuit in case all said contacts of said rotary bank level associated with said meter contact were busy during said rotary motion of said switch, and contacts controlled responsive to said release of said line relay subsequent to all said contacts of said rotary bank level beingv busy for opening said circuit to said slow-to-release relay and for completing said prepared meter circuit to operate said meter, said metering circuit maintained completed by said slow-to-release relay for a period of time equal t0 the release time of said slow-to-release relay.

4. In a two-motion automatic switch, a vertical bank having a plurality of contacts and a rotary bank having a plurality of contacts arranged in a plurality of levels, each contact of said vertical bank being associated with a diierent one of said rotary bank contact levels, a pair of meters associated with said switch, one of said meters being connected to a certain one of said vertical bank contacts and the other of said meters being vconnected to the remainder of said vertical bank contacts in multiple, means for busying certain of said rotary bank contacts, a vertical wiper on said switch having access to said vertical bank contacts, other wipers on said switch having access to said rotary bank contact levels, means for operating said switch in a vertical motion to simultaneously move said vertical wiper into engagement with one of said vertical bank contacts and position said other wipers opposite the rotary bank level associated with said one vertical bank contact, means for operating said switch in a rotary motion to move only said other wipers across said contacts of said rotary bank level associated with said one vertical bank contact while maintaining said vertical wiper in engagement with said one contact, a circuit at times including said vertical wiper and said certain vertical bank contact for operating said one meter and at other times including said vertical wiper and any one of said multipled remainder of vertical bank contacts for operating said other meter, and means for at times completing said circuit to operate said one meter in case all said contacts of said rotary bank level associated with said certain vertical contact were busy during said rotary movement of said switch and for at other times completing said circuit to operate said other meter in. case al1 said contacts of any one of the remainder levels associated with said remaining multipled vertical contacts were busy during said rotary movement of said switch.

CLARENCE E, LOMAX.

RiniEaFNorsl CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,551,773 Ray Sept. 1, 1925 1,862,532 Ferguson June 14, 1932 FOREIGN PATENTS Number Country Date 366,569 Great Britain Feb. 8, 1932 386,381 Great Britain Jan. 19, 1933 517,702 Great Britain Feb. 6, 1940 

